This project deals with how a cell can integrate gene expression so as to coordinate cellular activities during both normal growth and nutritional deficiency. Previous project work has described the discovery and characterization of an unusual nucleotide (ppGpp) that apparently regulates the expression of probably half of the genes in E. coli. Current work has taken two approaches towards understanding how the ppGpp mediated regulation operates. The first is the isolation of new mutants that are defective in the ability to accumulate ppGpp as well as the isolation of mutants that behave as if they are resistant to the usual regulatory effects of high levels of ppGpp. Several mutants of both sorts have been isolated, shown to be genetically distinct and are now being biochemically characterized. Secondly, we have isolated a gene expression system in which normal regulatory effects of ppGpp can be precisely evaluated. We have cloned a ribosomal RNA promoter region from E. coli plasmid (Co1 E1). Surprisingly this promoter region contains two tandem start sites, rather than one, which direct transcription of the sense strand of the rRNA cistron.